There is no question that many Jews have been turned off by the co-opting of the church and scripture by the Gentiles. By listening to what is said in many churches it's hard to recognize that 1) Jesus was a Jew, 2) Jesus followed the law of Moses, 3) Jesus taught in synagogues, 4) James, Peter, John, Matthew, Mark, Paul, and others were all Jews, 5) the bible in use at the time was the Hebrew Bible only (there was no New Testament, 6) all the feasts that were observed were Jewish, etc.
Romans 11 says in part "If some of the branches have been broken off, and you, though a wild olive shoot, have been grafted in among the others and now share in the nourishing sap from the olive root, do not consider yourself to be superior to those other branches. If you do, consider this: You do not support the root, but the root supports you. You will say then, “Branches were broken off so that I could be grafted in.” Granted. But they were broken off because of unbelief, and you stand by faith. Do not be arrogant, but tremble. For if God did not spare the natural branches, he will not spare you either. [emphasis mine, of course]
The gospel is preached relevant to each culture, but it's very unfortunate that so many have forgotten that the Jews only were the founders of the early church, and that the entire bible (with the possible exception of Luke) -- every single word of it -- was written by Jews, and when the Word became flesh, he was a 100% Jew.